The tiny briefcase-sized ships launched past year on a risky mission to "push the limits of experimental technology".
InSight would use the reliable Mars Reconnaissance Orbiter, which has been at Mars since 2006, to relay data back home, whether or not the CubeSats made it - but WALL-E successfully sent back InSight data from each stage of the descent, as well as the lander's first image, while EVE was able to perform some radio measurements. NASA estimated that Wall-E is more than a million miles (1.6 million kilometres) past Mars, and Eve is further away at nearly two million miles (3.2 kilometres).
A pair of small satellites that joined the InSight mission on its way to Mars haven't been heard from in over a month-but the experimental mission is still an important success for NASA.
The two probes, named after characters from a famous animated film by Pixar, became space pioneers for having the latest technology called CubeSats - small and relatively cheap satellites, capable of operating in deep space.
WALL-E, which had been leaking fuel since liftoff last May, last radioed back on December 29.
It's now more than 1 million miles (1.6 million kilometers) beyond Mars.
Nasa has several theories about why it has lost contact with the pair - none of which involve the interference of aliens.
Wall-E had a leaky thruster, and attitude control issues could be causing it to wobble and lose the ability to send and receive commands.
"The brightness sensors that allow the CubeSats to stay pointed at the Sun and recharge their batteries could be another factor", NASA JPL added in the statement.
The MarCO cubesats will most likely remain orbiting around the sun and will only get farther away from the star as the month continues.
The farther they are, the more precisely they need to point their antennas to communicate with Earth. The team will reattempt to contact the CubeSats at that time, though whether their batteries and other parts will last that long cannot be predicted.
After that, the team said if they made it that far it would already be a major success.
"This mission was always about pushing the limits of miniaturized technology and seeing just how far it could take us". "We've put a stake in the ground". Inside the dome, the seismometer is also contained in a titanium, vacuum-sealed container, the combination of which helps insulate the instrument even further from environmental hazards. A number of the critical spare parts for each MarCO will be used in other CubeSat missions.
JPL spokesman Andrew Good said February 5 that after the flyby the MarCO cubesats continued to transmit technical data about the performance of their various subsystems, including attitude control, propulsion and communications.